Comparison of Intraocular Pressure Measurements Obtained Using Three Tonometers after Descemet Membrane Stripping Endothelial Keratoplasty

Purpose: To compare the level of agreement between the Goldmann applanation tonometer (GAT), iCare IC200 rebound tonometer (IRT), and noncontact tonometer (NCT) in patients who underwent Descemet membrane stripping endothelial keratoplasty (DSEK), and to identify factors contributing to variations in intraocular pressure (IOP) measurements among the three tonometers.Methods: We retrospectively analyzed the medical records of 41 patients who underwent DSEK. IOP was measured using NCT, IRT, and GAT, in this order. We evaluated the level of agreement among IOP measurements using the three tonometers, and analyzed whether clinical factors affected the results.Results: We analyzed 49 eyes of 41 patients (average age: 62.0 years). The IOP values measured by IRT and NCT were lower than those measured by GAT, although the difference was not significant (p = 0.098 and p = 0.320, respectively). A Bland-Altman plot showed greater agreement between IOP measurements obtained by IRT and GAT than those obtained by NCT and GAT. In multivariate regression analysis, the IOP measured by GAT (8 = 0.215, p = 0.022), corneal curvature (8 =-1.692, p = 0.037), and postoperative duration (8 = 0.042, p = 0.018) affected the difference in IOPs measured by GAT and IRT. The IOP measured by GAT (8 = 0.301, p = 0.013) and corneal curvature (8 =-2.670, p = 0.010) affected the difference in IOP measurements obtained by GAT and NCT.Conclusions: In DSEK eyes, IRT showed good agreement and high correlation with GAT, suggesting that it is useful for IOP measurement. However, the IOP measured by GAT, corneal curvature, and postoperative duration should be considered when measuring IOP with an IRT.